Real Sociedad will demand huge money to sell Martin Zubimendi.
The midfielder is a top target for Barcelona, where he is viewed as a successor for Sergi Busquets.
Busquets' contract expires in June and he is set to leave Europe and move to MLS.
Sport says Barca have already identified Zubimendi as a priority to replace their captain.
However, La Real will demand top price for the player, insisting he won't leave for less than €50m. Zubimendi's contract carries a €60m buyout clause.
